My first impressions is that this is a neat little console that has its uses for adult gamers that have kids, and limited TV access rather than on the go gaming. I only used it in portable mode for a motion controlled shrine on Zelda. The controller seemed to be off center with the gyroscope so I swapped to handheld mode and it was a little better. I think it had more to do with the game. The screen is nice and crisp, but definitely not the Super AMOLED screens you're use to seeing on android devices. I'm sure this has to do with battery life.
The console is very small and light weight, but not small enough to stick in your pocket and go around with. The only transportation I'd feel comfortable with is bringing the whole system to a friends house to show off.
For someone like me that is going to play this docked 99.9% of the time, the pro controller is a must. No debate. The joycon buttons are tiny and the sticks are as well. This leads to an over sensitivity that I just can't get use to. I'm glad everyone was out of the charging grip, making me decide to buy this controller. It feels great in the hands, and has a nice 90s retro feel at the same time. Its like an Xbox 360 controller had a lovechild with a Sega Genesis controller. I say that because that's what the triggers feel like... just mashed buttons. There is no refined pull like ps4/xb1's offerings. But I doubt that the FPS genre will be huge on switch anyways. The Joycon's triggers are pretty much the same, just smaller.
The biggest upside for me is that the Switch isn't a blast furnace like the bigger consoles. Its small, quiet, and generates no head out of its exhaust vent. I can easily leave my PC on and not suffocate in electronically generated humidity. This is great because I can leave my PC running for guides instead of using my phone.
The framerate in docked mode is worse than mobile for Zelda. This is odd, but I think its because the game gets scaled with what is the equivalent of maxing shaders and shadows on a PC game. Since the dock doubles the power of the switch almost, you would think it could handle it, but I want to say this is mostly because BoTW is a port that hasn't been properly optimized. The only time the framerate drop gets bad is when you're going full speed on a horse through woods with tall grass and goblins are jumping out everywhere. It got BAD, outside of that it wasn't much of an issue. Tall grass, and running water seem to drag it down the most.
The biggest downside to the Switch is that its pretty much just a gaming console. With something this mobile its a shame thats all you can do. The options menu is pretty basic, and outside the store there is nothing else to do in Switch's UI. No web browser, no streaming services, no virtual console (yet), and no real sign of any online perks to justify paying a monthly sub fee. The internet connection only serves as an update tool... and it updates pretty fast. A lot faster than PS4 and its "preparing to download" segment. So yeah, there is plenty of time to wait and see how the switch evolves and what games come out for it. Right now its just a Zelda machine.